1. Field of the Invention
The invention relates generally to aquatic toxicity testing and, more particularly, but not by way of limitation, it relates to improvements in both method and apparatus for toxicity testing liquid samples by quantifying the effects of the subject sample on Daphnia sp. or other aquatic species.
2. Description of the Prior Art
The prior art includes several types of testing methods for determining aquatic toxicity, and in most cases the prior methods attempt to derive a quantifiable result. A system known as chronic Whole Effluent Toxicity (WET) test is a relatively economical toxicity testing system that uses EPA-approved methods and test organisms; however, such a system has very limited portability and requires seven days to perform a single test. This biological test method uses representative organisms to estimate the effects of effluents discharged or receiving waters on the eco system.
Another assay system known as the MICROTOX.RTM. Toxicity Test utilizes the luminescent marine microorganisms which are altered as to light emission by changes in their metabolic processes. Reduction of light is proportional to toxicity of the sample. A testing reagent containing the microorganisms is freeze-dried for storage and is readily reconstituted for testing in a very short time. Finally, a toxicity test known as the IQ Test Kit.TM. provides a low price test system but one that does not produce quantifiable results. This test requires initial preparation of the test sample with organisms for subsequent irradiation in ultraviolet light (longwave). Acquired test data is then interpreted by means of other conventional assay methods.